JP2013044931A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector having a high contrast ratio and capable of suppressing an irregular color, with a simple structure and at an economical price.SOLUTION: A projector of this invention includes: a light source; an illumination optical system having a light-shielding mechanism capable of partially light-shielding light flux from a light source; and an optical modulator to be irradiated by illumination light from the illumination optical system. The light-shielding mechanism includes a pair of light-shielding plate parts rotatable around a predetermined rotational axis to change a size of a light-shielding region. The pair of light-shielding plate parts include: a first light-shielding part extending in a direction approximately orthogonal to an optical axis when reaching a maximum light-shielding position; and a second light-shielding part slanted with respect to the first light-shielding part such that a tip side is removed from the first light-shielding part on an emission side of the illumination light with respect to the first light-shielding. One base material is bent to form the first light-shielding part and the second light-shielding part.

Description

  The present invention relates to a projector.

  As a projector using a light shielding plate for adjusting an illumination device, for example, a pair of plate-shaped light shielding plates that can be opened and closed by rotation, with an illumination optical axis sandwiched between a pair of lens arrays in the illumination device There are known devices that adjust the amount of illumination light blocked. In addition, a block-shaped light shielding body is used as such a light shielding plate portion, and a notch is provided in the light shielding body to adjust a change in the light shielding amount. However, when a block-shaped light shielding body having such a notch is used as the light shielding plate portion, it is necessary to form a complicated curved surface at the end of the light shielding body in order to change the light shielding amount as desired. . In this case, a space for the light shield is also required, but there are spatial limitations around the pair of lens arrays, and it may be difficult to install a block-shaped light shield.

  Therefore, the light shielding part has a first light shielding plate part and a second light shielding plate part, and the first light shielding plate part has a notch, thereby making the change in the light shielding amount comparatively gentle. And the second light-shielding plate portion changes the light-shielding region corresponding to the cutout portion to shield all or part of the light flux corresponding to the cutout portion when the first light-shielding plate portion is fully closed. A configuration has been proposed (Patent Document 1).

JP 2010-217651 A

  However, since the first light-shielding plate portion and the second light-shielding plate portion are separately formed and then integrated by caulking, welding, etc., it is difficult to increase the number of parts and assembly man-hours and to ensure long-term reliability. There is a problem.

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a projector with a low contrast and a high contrast ratio while suppressing color unevenness with an inexpensive and simple configuration.

  The projector of the present invention includes a light source, an illumination optical system having a light shielding mechanism capable of partially shielding a light beam from the light source, and a light modulation device illuminated by illumination light from the illumination optical system, The light-shielding part has a pair of light-shielding plate parts that change the size of the light-shielding region by rotating around a predetermined rotation axis, and when the light-shielding plate part is at the maximum light-shielding position, A first light-shielding portion extending in a direction substantially orthogonal to the optical axis; and the first light-shielding portion such that a distal end side is separated from the first light-shielding portion on the illumination light exit side with respect to the first light-shielding portion. The second light-shielding part is inclined with respect to the first light-shielding part, and the first light-shielding part and the second light-shielding part are formed by folding one base material.

  According to such a configuration, the first light-shielding portion and the second light-shielding portion are configured by folding back one base material, so that the number of parts can be reduced, and work such as welding is not necessary, so that manufacture is easy. become. Also, discoloration due to welding can be prevented. Furthermore, since the first light-shielding part and the second light-shielding part are not completely separated during use, long-term reliability is also ensured.

Moreover, it is good also as a structure by which the both ends of the said base material by which it turned back are crimped and fixed mutually.
According to such a structure, since both ends can be positioned by the caulking holes, positioning holes are not required and the size is reduced. Moreover, manufacture is easy.

Moreover, it is good also as a structure which crimps and fixes with respect to the connection member whose heat conductivity is smaller than the said base material at least one edge part of the said base material.
According to such a configuration, the temperature of the light shielding plate part that has been irradiated from the light source is less likely to be transmitted to the drive unit via the connecting member.

Moreover, it is good also as a structure by which the said base material is return | folded from the direction which cross | intersects the opening-and-closing direction of the said optical axis and the said light-shielding board part.
According to such a structure, since the folding | turning part of a base material differs from the opening-and-closing direction of a light-shielding plate part, the light-shielding plate part which has a favorable light-shielding characteristic is obtained.

FIG. 2 is a perspective view illustrating a configuration of the projector according to the embodiment. FIG. 2 is a diagram schematically illustrating a schematic configuration of a projector. The figure which shows the internal structure of a projector. The partial expanded sectional view centering on a light control mechanism. The exploded view which shows the structure of a light control mechanism. The figure which shows the positional relationship of a light-shielding plate part and a lens array. (A), (b) is a figure which shows concretely the whole structure of a light control mechanism. It is a figure which shows the structure of a pair of light-shielding shutters concretely, Comprising: (a) is the perspective view seen from the 1st lens array side, (b) is the inclination figure seen from the 2nd lens array side. (A) is a top view which shows the structure of a pair of light shielding shutter, (b) is a side view of (a). The perspective view for demonstrating operation | movement of a light control mechanism. Sectional drawing for demonstrating operation | movement of a light control mechanism. It is a figure which shows the maximum open state (full open state), Comprising: (a) is a side view, (b) is the figure seen from the optical axis side. It is a figure which shows the maximum light-shielding state (fully closed state), Comprising: (a) is a side view, (b) is the figure seen from the optical axis side. The conceptual diagram for explaining in detail about the change of the light-shielding amount (the passage amount of illumination light) by operation | movement of a light control mechanism. The figure which shows the other structural example of a light control mechanism.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[projector]
Hereinafter, the projector according to the present embodiment will be described with reference to the drawings.
The projector according to the present embodiment modulates a light beam emitted from a light source according to image information to form image light, and enlarges and projects the image light.
FIG. 1 is a perspective view illustrating the configuration of the projector according to the present embodiment, and is a view in which a cable cover is removed. FIG. 2 is a diagram schematically illustrating a schematic configuration of the projector.

  As shown in FIG. 1, the projector 1 has a configuration in which a main body (projector main body) 1 </ b> A is surrounded by an outer casing 2. The exterior casing 2 is made of synthetic resin, and includes an upper case (first case) 21 that constitutes the upper part of the casing, a lower case (second case) 22 that constitutes the lower part of the casing, and the like. It is fixed with screws.

  Further, as shown in FIG. 2, a control unit 10, an optical unit 3, a power supply unit 4, a cooling fan 51, an exhaust fan 52, and the like are arranged in the exterior housing 2. The optical unit 3 is configured in a substantially L shape in plan view, and includes a light source device 31 having a light source 311, an electro-optical device 35, and a projection optical device (projection optical system) 36. The optical unit 3 optically processes the light beam emitted from the light source 311 under the control of the control unit 10 to form image light corresponding to the image information by the electro-optical device 35, and this image light is projected optically. An image is displayed on a screen or the like by the device 36.

  The light source device 31 is disposed at the end of the exterior housing 2, and the projection optical device 36 is disposed at a substantially central portion of the exterior housing 2. In the following, for convenience of explanation, the direction in which the light beam is emitted from the light source device 31 is the + X direction, and the direction in which the image light is emitted from the electro-optical device 35 is the + Y direction. The combination direction of 22 is defined as the Z direction.

  The control unit 10 is configured as a circuit board on which a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are mounted. The control unit 10 functions as a computer and performs control of the operation of the projector 1, for example, control related to image projection. Note that the position of the control unit 10 shown in FIG. 2 is schematically shown and is different from the actual position. Although described later in detail, the control unit 10 is actually arranged so as to cover the optical unit 3.

  Then, referring back to FIG. 1, a recess 210 is formed on the upper surface of the upper case 21 of the exterior casing 2 that accommodates each of the above components, and one inclined surface constituting the recess 210 is further viewed in a plan view. A rectangular recess 211 is formed. A projection window 201 is provided on the bottom surface of the recess 211, and image light emitted from the projection optical device 36 is behind the exterior casing 2 from the projection window 201 (on the lamp cover 24 side in FIG. 2). It is injected towards. Here, when an object that blocks the projection light is placed on the projection window 201 by the user, it can be detected by the foreign matter detection sensor (not shown). The control unit 10 warns the user when a foreign object detection signal is input from a foreign object detection sensor (not shown).

  An operation unit 23 including a plurality of operation keys for performing various settings of the projector 1 is provided in front of the upper case 21. In addition, an opening 212 for replacement of the light source device 31 is formed behind the upper case 21, and the opening 212 is closed when the lamp cover 24 is attached to the upper case 21.

  An intake port 220 for taking in outside air is provided on the left side (side surface 2B) of the exterior housing 2. The intake port 220 is formed by a plurality of rectangular slit holes, and a dustproof filter (not shown) is disposed inside the intake port 220. The optical unit 3 is cooled by the air taken from the air inlet 220 and passing through the dustproof filter.

  In addition, an exhaust port 222 for discharging warm air inside is provided on the right side (side surface 2C) of the exterior housing 2. The exhaust port 222 is formed of a plurality of slit holes, and the air in the exterior casing 2 warmed by the lighting of the light source 311 (FIG. 2) or the like is discharged from the exhaust port 222 to the outside. In the lower case 22, a rectangular recess 211 is formed in front of the exhaust port 222, and a plurality of cables connected to the projector 1 are accommodated in a space formed by the recess 211.

[Optical unit]
Next, each component of the optical unit will be described in detail with reference to FIGS.
FIG. 3 is a diagram illustrating an internal configuration of the projector.
As shown in FIGS. 2 and 3, the optical unit 3 has an L shape in plan view, and includes a light source device 31, an illumination optical device (illumination optical system) 32, a color separation optical device 33, a relay optical device 34, and an electro-optical device. A device 35, a projection optical device 36, and an optical component housing 37 for arranging these optical components 31 to 36 at predetermined positions are provided.

  The light source device 31 includes a discharge-type light source 311 including a super-high pressure mercury lamp and a metal halide lamp, a reflector 312 and the like. Then, the light source device 31 aligns the emission direction of the light beam emitted from the light source 311 with the reflector 312 and emits it toward the illumination optical device 32.

The illumination optical device 32 includes a first lens array 321, a second lens array 322, a polarization conversion element 323, a superimposing lens 324, and a light adjustment mechanism (light shielding mechanism) 325.
The first lens array 321 has a configuration in which small lenses having a substantially rectangular outline when viewed from the direction of the optical axis L of the light beam emitted from the light source 311 are arranged in a matrix, and emitted from the light source device 31. The divided light beam is divided into a plurality of partial light beams. The second lens array 322 has substantially the same configuration as the first lens array 321, and, together with the superimposing lens 324, the partial light beam is substantially superimposed on the surface of a liquid crystal light valve (light modulation element) 352 described later. The polarization conversion element 323 has a function of aligning randomly polarized light emitted from the second lens array 322 with substantially one type of polarized light that can be used by the liquid crystal light valve 352.

  The light control mechanism 325 includes light-shielding shutters (light-shielding portions) 326 and 327 (FIG. 4) that shield a part of the light beam emitted from the light source 311 and has a function of adjusting the amount of light passing through the light beam. Although the detailed configuration will be described later, the light control mechanism 325 is configured to block a part of the light beam emitted from the light source 311 and transmitted through the first lens array 321 under the control of the control unit 10. In FIG. 4), the amount of light incident on the second lens array 322 after being shielded is adjusted, and thus the amount of light incident on the electro-optical device 35 is adjusted to contribute to the improvement of the contrast of the projected image.

  The color separation optical device 33 includes two dichroic mirrors 331 and 332, and a reflection mirror 333. A light beam emitted from the illumination optical device 32 is converted into red light (hereinafter referred to as “R light”), green light (hereinafter referred to as “G light”). Light) and blue light (hereinafter referred to as “B light”).

  The relay optical device 34 includes an incident side lens 341, a relay lens 343, and reflection mirrors 342 and 344, and has a function of guiding the R light transmitted through the second dichroic mirror 332 to the R light liquid crystal light valve 352R. The optical unit 3 has a configuration in which the relay optical device 34 guides the R light. However, the configuration is not limited to this. For example, the optical unit 3 may have a configuration that guides the B light.

  The electro-optical device 35 includes an incident-side polarizing plate 351, a liquid crystal light valve 352 as a light modulation device, an emission-side polarizing plate 353, and a cross dichroic prism 354 as a color combining optical device, and is emitted from the color separation optical device 33. Each color light is modulated in accordance with image information.

  The projection optical device 36 includes a combined lens in which a plurality of lenses are combined and an aspherical reflection mirror 38. The projection optical device 36 emits the light beam modulated by the electro-optical device 35 from the assembled lens to the reflection mirror 38, and reflects and projects the light beam so as to widen the angle by the reflection mirror 38. With such a structure, it can be configured as a so-called short focus projector with a short projection distance. The direction of the light beam emitted from the combined lens to the reflection mirror 38 is referred to as the projection direction in the projection optical device 36.

  The power supply unit 4 rectifies and smoothes the AC power supplied from the external power supply, and outputs it to the light source 311 and the control unit. The power supply unit 4 is disposed below the light source device 31. Specifically, it is housed in a power supply case 20 (FIG. 3) attached to the bottom of the lower case 22.

  The cooling fan 51 is configured by a sirocco fan that discharges air sucked from the rotation axis direction in the rotation tangential direction, and is disposed inside the intake port 220 and in the vicinity of the relay optical device 34. The cooling fan 51 is arranged so that the suction port 511 for sucking outside air faces the suction port 220 side, and the discharge port 512 for discharging air faces the relay optical device 34 side. The cooling fan 51 cools the relay optical device 34 by discharging the outside air taken in by the suction port 511 toward the relay optical device 34 that generates heat. Hereinafter, the direction in which the cooling fan 51 discharges air is referred to as “discharge direction”.

  The exhaust fan 52 is an axial fan, and is disposed inside the exhaust port 222 and between the light source device 31. The exhaust fan 52 discharges the air heated by cooling the light source device 31 and the like to the outside of the exterior casing 2 through the exhaust port 222.

  The control unit 10 includes a main circuit board 53 and a driver board 54 on which a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like are mounted. Alternatively, the projector 1 is controlled autonomously.

  For example, the control unit 10 controls the lighting of the light source device 31 described above and generates a drive signal corresponding to an image signal input via the operation unit 23 and outputs the drive signal to the electro-optical device 35. When generating the drive signal, the control unit 10 executes processing such as image quality adjustment according to the parameters set by the user. Such a control unit 10 includes, for example, a storage unit, an information acquisition unit, an image generation unit, a drive control unit, an information storage unit, and the like.

[Dimming mechanism]
Next, the configuration of the light control mechanism will be described in detail.
4 is a partially enlarged cross-sectional view centering on the light control mechanism, FIG. 5 is an exploded view showing the configuration of the light control mechanism, and FIG. 6 shows the positional relationship between the light shielding plate and the lens array. FIG.
As shown in FIG. 4, the light control mechanism 325 includes a pair of light shielding shutters (light shielding plate portions) 326 and 327 disposed between the first lens array 321 and the second lens array 322. ing. Such a light control mechanism 325 is inserted so that the light shielding shutters 326 and 327 are inserted from the side of the optical component housing 37 from the side of the illumination optical device 32 as shown in FIG. 360 is assembled to the optical component housing 37 by screwing. In the assembled state, the light control mechanism 325 is arranged so that the respective light-shielding shutters 326 and 327 are arranged along the surface direction between the first lens array 321 and the second lens array 322 as shown in FIG. Arranged vertically.

  FIGS. 7A and 7B are diagrams specifically showing the overall configuration of the light control mechanism. FIG. 8 is a diagram specifically showing the configuration of a pair of light shielding shutters, where (a) is a perspective view seen from the first lens array side, and (b) is a perspective view seen from the second lens array side. It is. FIG. 9A is a plan view showing the configuration of a pair of light shielding shutters, and FIG. 9B is a side view of FIG.

As shown in FIGS. 7A and 7B, the light control mechanism 325 includes a pair of light shielding shutters 326 and 327 and a pair of light shielding shutters 326 and 327 that can partially shield the light flux from the light source device 31. And a drive unit 329 to be operated.
The drive unit 329 includes a plurality of gear units 361, 362, 363, 364, a stepping motor 365 for rotating the gear unit 364, and a plate member 360 for holding them. The gear portion 364 is a drive gear attached to the rotation shaft of the stepping motor 365, and rotates in the clockwise direction or the counterclockwise direction. The gear parts 361 to 363 are driven gears and interlock with the rotation of the gear part 364.

  The light shielding shutter 326 is attached to the plate member 360 via the first gear portion 361, and the light shielding shutter 327 is attached to the plate member 360 via the second gear portion 362. The first gear portion 361 and the second gear portion 362 are engaged with each other, and the third gear portion 363 is engaged with the second gear portion 362 side. The third gear portion 363 meshes with the fourth gear portion 364 connected to the stepping motor 365. Then, the driving force of the stepping motor 365 is transmitted to the third gear portion 363 via the fourth gear portion 364, the second gear portion 362 and the first gear portion 361 rotate, and the light shielding shutters 326 and 327 move. It has a configuration. The light shielding shutters 326 and 327 move in conjunction with each other around the rotation axes of the gear portions 361 and 362 intersecting the optical axis L.

  The dimming mechanism 325 includes a meshing position detection sensor 366 for detecting the meshing position of the first gear part 361 and the second gear part 362. The meshing position detection sensor 366 is composed of an optical element, and is installed at a location where the number of teeth of the second gear portion 362 can be detected, for example. The meshing position detection sensor 366 detects the number of teeth of the second gear portion 362, thereby detecting the rotation amount of the second gear portion 362. As described above, the light shielding shutter 327 moves with the rotation of the second gear portion 362, and the light shielding shutter 326 moves with the rotation of the first gear portion 361. That is, since the first gear portion 361 rotates in accordance with the rotation amount of the second gear portion 362, the light shielding shutter 326 and the light shielding shutter 327 are detected by detecting the rotation amount of the second gear portion 362 by the meshing position detection sensor 366. Can be controlled.

  FIGS. 8A, 8B, and 9 show the configuration and arrangement state of the light shielding shutters 326 and 327 at the maximum light shielding position. As shown in these drawings, the light shielding shutters 326 and 327 are arranged such that the leading end portions 326a and 237a overlap each other on the optical axis L in the optical axis direction at the maximum light shielding position.

  Each of the light shielding shutters 326 and 327 includes one base material 100, and is formed into a desired shape by folding back the base material 100 in the longitudinal direction. The light-shielding shutter 326 has a light-shielding plate portion 6 and a light-shielding plate portion 7 that face each other when a part of the base material 100A is folded back, and the optical axis L (FIG. 9B) at the maximum light-shielding position. The light shielding portion (second light shielding portion) 71a of the light shielding plate portion 7A is inclined with respect to the light shielding portion (first light shielding portion) 61a of the light shielding plate portion 6A extending in a direction substantially orthogonal to the light shielding plate 6A. Specifically, the light-shielding part 71a is configured to be inclined with respect to the light-shielding part 61a on the illumination light exit side with respect to the light-shielding part 61a and the tip side away from the light-shielding part 61a.

  The substrate 100 is made of an aluminum plate, and the folding direction coincides with the direction (the axial direction of the rotation axis O) intersecting the optical axis L and the opening / closing direction of the light shielding plates 6 and 7. Therefore, the folded portion 110 is formed on one end side in the length direction of the light shielding plate portions 6 and 7. The both end portions 101a and 101b of the folded base material 100 are aligned using the caulking holes 102 formed in advance in each, and then caulked using caulking pins (not shown). Accordingly, the end portions 101a and 101b are securely fixed without being separated by the reaction force of the folded portion 110.

  A caulking pin (not shown) for joining the connecting member 301 (302) is inserted into another caulking hole 103 formed in the end 101b. The light blocking shutter 326 is connected to the first gear portion 361 via the connecting member 301, and the light blocking shutter 327 is connected to the second gear portion 362 via the connecting member 302. The connecting members 301 and 302 and the gear portions 361 and 362 are fixed using a fixing pin 120 or the like.

  The connecting members 301 and 302 are made of a material having a lower thermal conductivity than the base material 100, and are made of SUS in this embodiment. Thereby, it is possible to suppress the heat of the light-shielding shutters 326 and 327 that are heated by receiving light irradiation from the light source device 31 from being conducted to the gear portions 361 and 362 of the drive unit 329.

  Similarly, the light shielding shutter 327 is also configured by being folded back in the longitudinal direction of one base material 100. The light-shielding shutter 327 has a light-shielding plate portion 6 and a light-shielding plate portion 7 that face each other when a part of the base material 100A is folded back, and the optical axis L (FIG. 9B) at the maximum light-shielding position. The light shielding portion (second light shielding portion) 71a of the light shielding plate portion 7A is inclined with respect to the light shielding portion (first light shielding portion) 61a of the light shielding plate portion 6A extending in a direction substantially orthogonal to the light shielding plate 6A.

Here, in the direction orthogonal to the optical axis L, the overlapping state of the light shielding portions 61a and 61b is equal to each other, and the distances from the optical axis L to the tips of the light shielding portions 61a and 61b are also equal.
Further, they are arranged to face each other with a predetermined distance across the optical axis L. The distances from the tips of the light shielding portions 71a and 71b to the optical axis L are equal. Furthermore, the distances between the light shielding portions 71a and 71b and the second lens array 322 are also equal. As a result, when the light shielding shutters 326 and 327 are rotated, the light shielding positions in the light shielding portions 71a and 71b are the same contrasting positions via the optical axis L, and a desired illuminance distribution is obtained.

  Further, the light shielding shutter 326 and the light shielding shutter 327 of this embodiment are shifted from each other in the direction away from the optical axis direction, and the light shielding shutter 326 is located farther from the second lens array 322 than the light shielding shutter 327. Therefore, in order to make the distance between the tip of each light shielding part 71a, 71b and the second lens array 322 equal, the light shielding of the light shielding shutter 327 located on the front side in the optical axis direction (first lens array 321). The part 71b has a length longer than the light shielding part 71b of the light shielding shutter 326.

Further, the light shielding plate portions 6A and 6B are respectively formed with first cutout portions 320 on both ends in the width direction. These first notches 320 are for preventing the light emitted from the light source device 31 from being completely shielded at the maximum light shielding position, and a part of the emitted light leaks through each first notch 320. To be emitted.
Further, arc-shaped second notches 330 are formed at the center portions in the width direction of the tip portions 327a and 327b of the light shielding plate portions 7A and 7B. These second cutout portions 330 are for controlling the light shielding amount on the light flux center side of the illumination light emitted from the light source device 31.

  That is, the light shielding shutter 326 functions to adjust the light shielding amount on the light beam center side by the second notch 330 formed in the light shielding plate 7A from the fully open state to the fully closed state. In the fully closed state, the light shielding portion 61a of the light shielding plate portion 6A functions to adjust the light shielding amount around the light beam by the first notch portion 320 while maximizing the light shielding amount at the center of the light beam.

  Similarly, the light shielding shutter 327 functions to adjust the light shielding amount on the light beam center side by the second notch portion 330 formed in the light shielding plate portion 7B from the fully open state to the fully closed state. In the fully closed state, the light shielding portion 61b of the light shielding plate portion 6B functions to adjust the light shielding amount around the light beam by the first cutout portion 320 while maximizing the light shielding amount at the center of the light beam.

FIG. 10 is a perspective view for explaining the operation of the light control mechanism, and FIG. 11 is a cross-sectional view for illustrating the operation of the light control mechanism. FIG. 12 is a diagram illustrating a maximum open state (fully opened state), and FIG. 13 is a diagram illustrating a maximum light shielding state (fully closed state).
As shown in FIG. 10, the rotation of the stepping motor 365 of the dimming mechanism 325 is transmitted to the third gear portion 363 via the fourth gear portion 364 connected to the rotation shaft of the motor. With the rotation of the third gear portion 363, the second gear portion 362 and the first gear portion 361 rotate. At this time, the first gear part 361 and the second gear part 362 rotate in opposite directions in synchronization with each other. As a result, the light control mechanism 325 can open and close the light-shielding shutter 326 and the light-shielding shutter 327 in a double-speech manner in synchronization. At this time, the light-shielding shutters 326 and 327 change their states to a fully open state and a fully closed state as the stepping motor 365 rotates forward or backward. For example, as shown in FIG. 11, the light shielding shutters 326 and 327 are in a maximum light shielding state and a fully opened state by a rotation operation around the central axes AX1 and AX2 of the gear portions 361 and 362.

  Specifically, in the maximum light-shielding state indicated by the solid line in the drawing, the light-shielding shutters 326 and 327 are substantially parallel to the second lens array 322 and the tip portions 326a and 327a are aligned on the optical axis L. In the fully opened state indicated by the broken line in the figure, the light shielding shutters 326 and 327 rotate by a predetermined rotation angle θ1 (approximately 90 °) from the fully closed state substantially parallel to the second lens array 322, and the leading end portions 326a and 327a. Is located outside the optical path of the illumination light (outside the effective range) and there is no blocking of the illumination light.

  Although not shown, as a middle stage, the light-shielding shutters 326 and 327 rotate by a predetermined rotation angle θ2 (0 ° <θ1 <θ2) as compared to the fully closed state substantially parallel to the second lens array 322. However, the tip portions 326a and 327a are separated from the optical axis L to some extent, and a part of the illumination light is blocked.

Next, the operation of the light control mechanism will be specifically described.
12A and 12B are diagrams showing a fully opened state of the pair of shielding shutters, where FIG. 12A is a side view and FIG. 12B is a view as seen from the optical axis side.
When moving the light-shielding shutters 326 and 327 from the fully closed state to the fully open state, as shown in FIGS. 12A and 12B, when the stepping motor 365 rotates counterclockwise, the fourth gear is associated therewith. The part 364 rotates in the same direction, and the third gear part 363 rotates clockwise. Since the second gear portion 362 rotates counterclockwise in synchronization with the third gear portion 363, the first gear portion 361 rotates clockwise accordingly. As a result, the light-shielding shutters 326 and 327 are in a fully opened state that is furthest away from each other.

FIGS. 13A and 13B are diagrams showing the maximum light-shielding state (fully closed state), where FIG. 13A is a side view and FIG. 13B is a view seen from the optical axis side.
When moving the light-shielding shutters 326 and 327 from the fully open state to the fully closed state, as shown in FIGS. 13A and 13B, when the stepping motor 365 is rotated clockwise, the fourth gear portion is associated therewith. 364 rotates in the same direction, and the third gear portion 363 rotates counterclockwise. The second gear portion 362 rotates clockwise in synchronization with the third gear portion 363, and accordingly, the first gear portion 361 rotates counterclockwise. As a result, the light shielding shutters 326 and 327 partially overlap each other at a position closest to each other and coincident with the optical axis L, and are in a maximum light shielding state.

Next, the change of the light shielding area by the light control mechanism will be described.
FIG. 14 is a conceptual diagram for explaining in detail the change in the light shielding amount (illumination light passage amount) due to the operation of the light control mechanism.
As illustrated in FIG. 14, the light control mechanism changes the light shielding region of the light beam of the illumination light SL from the light source 311 by rotating the light shielding shutters 326 and 327 as in patterns P1 to P4, thereby changing the illumination light SL. Perform dimming. Pattern P1 shows a fully open state (rotation angle is approximately 90 °), and pattern P4 indicates a fully closed state (rotation angle is approximately 0 °). Patterns P1 to P4 show the difference in light shielding state depending on the rotation angle θ1 (0 ° <θ3 <θ2 <θ1 (90 °)).

  In the fully open state of the pattern P1, the value of the rotation angle θ1 is 90 °, and the light shielding shutters 326 and 327 are disposed at positions where the light flux from the light source 311 is not shielded. In this case, all components of the light flux emitted from the light source 311 pass and are used as the illumination light SL.

  When the light shielding shutters 326 and 327 are rotated so as to increase the light shielding area from the fully opened state to the pattern 2 state, a part of the illumination light SL is first shielded by the light shielding plate portions 7A and 7B. At this time, the light on the center side of the illumination light SL passes through the second cutout portions 330 of the light shielding plate portions 7A and 7B.

  Then, when the light shielding shutters 326 and 327 are further rotated so as to increase the light shielding area so that the pattern P3 is closed rather than the pattern P2, the light shielding plates 6A and 6B and the light shielding plates 7A and 7B are used. The illumination light SL is further shielded. At this time, a part of the light on the center side of the illumination light SL is transmitted through the second notch 330 while being partially shielded by the light shielding plates 6A and 6B.

When the light shielding shutters 326 and 327 are closed to make the pattern P4 fully closed, the illumination light SL is shielded only by the light shielding plates 6A and 6B. At this time, the illumination light SL is not completely shielded by the light shielding plates 6A and 6B, and the light on the center side of the illumination light is shielded by the light shielding parts 61a and 61b at the front ends. Peripheral light of the illumination light SL is partially transmitted so as to leak from the pair of first cutout portions 320 and 320 (FIG. 8A) provided on both sides.
As described above, when the light blocking shutters 326 and 327 are in the maximum light blocking state, blocking the light on the center side of the illumination light SL and partially transmitting the peripheral light contributes to improving the contrast.

As described above, the projector 1 according to the present embodiment includes the light control mechanism 325 having the pair of light shielding shutters 326 and 327, and rotates the light shielding shutters 326 and 327 around a predetermined rotation axis to generate a light source. Light is adjusted by partially blocking the light beam from 311.
Each of the light-shielding shutters 326 and 327 is formed by folding a single base material 100, and is easy to manufacture and can eliminate problems during use. That is, if the light shielding plate portions 6 and 7 that the shutters 326 and 327 respectively have are formed using different base materials, a step of bonding the light shielding plate portions 6 and 7 to each other becomes necessary. . When these two parts are joined by spot welding or the like, the welded portion is discolored and heat is accumulated in that portion. The welded part that has become hot gradually melts. In addition, if the welded portion has a shape outside the optical path of the illumination light (outside the effective range), the shielding shutter not only increases in size, but also has a problem in terms of strength due to partial joining.
Similarly, when two parts are caulked and joined, discoloration may occur in the joined portion, or the surface may become rough, resulting in a high temperature. In addition to this, there is a problem that the number of processing steps increases.

On the other hand, the light shielding shutters 326 and 327 of the present embodiment have the light shielding plate portions 6 and 7 formed from opposing portions by folding one base material 100 at a predetermined position. There is no need for welding. For this reason, the discoloration by joining, etc. do not arise, but even when it reaches a certain high temperature, it is possible to avoid the problem of partial melting.
Moreover, in this embodiment, the edge parts 101a and 101b of the base material 100 which faced by folding are fixed using a crimp pin (not shown) or the like. Since this caulking is to prevent separation between the end portions 101a and 101b, only one place is required for each base material 100. Temporarily, it is difficult to maintain the state in which the two plate members are aligned for a long period of time only by caulking and fixing at one location, and fixing at a plurality of locations is required.
Therefore, with the configuration of the present embodiment, the number of processing steps is reduced, manufacturing becomes easy, and the problem of strength is solved unlike partial bonding. Furthermore, since the end portions 101a and 101b with a small amount of illumination light are caulked, deterioration due to heat of the caulking portions can be suppressed.

  Further, in the light control mechanism 325 of the present embodiment, the pair of light shielding shutters 326 and 327 are arranged along the optical axis L, so that the light shielding portions 61a and 61b overlap when fully closed, thereby illuminating light. Among them, the central light with the highest luminance can be completely blocked. Thereby, a desired contrast can be obtained.

  Furthermore, the first cutout portion 320 and the second cutout portion 330 can make the change in the light shielding amount relatively gentle and can sufficiently reduce the amount of illumination light in the maximum light shielding state. Further, the light-shielding shutters 326 and 327 and the peripheral structure thereof can be manufactured at low cost with a simple configuration, and a high-performance projector capable of projecting a display image with a high contrast ratio at a reduced cost can be obtained.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the previous embodiment, the configuration in which the pair of light shielding shutters 326 and 327 are arranged so as to be displaced in the optical axis direction has been described. However, as shown in FIG. 15, the positions of the light shielding shutters 326 and 327 are aligned in the optical axis direction. You may arrange | position so that it may correspond. In this case, the tip portions 326a and 327a of the light shielding shutters 326 and 327 come into contact with each other when fully closed. Further, in the case of such a configuration, it is preferable that the light shielding actions of the light shielding shutters 326 and 327 that rotate in synchronization are equal to each other.

  Further, the folding direction of the base material 100 constituting the light shielding shutters 326 and 327 does not have to coincide with the horizontal direction orthogonal to the optical axis L. For example, the folded portion 110 may be formed on the tip side of the light shielding portions 61a and 61b of the light shielding plate portions 6A and 6B, or the opposite end of the light shielding plate portions 6A and 6B to the light shielding portions 61a and 61b. The folded part 110 may be formed in the part.

  In the previous embodiment, the second cutout portion 330 is provided. However, the present invention is not necessarily limited to this, and the second cutout portion 330 may not be provided. However, it is desirable to provide the second notch 330 for suppressing color unevenness.

  DESCRIPTION OF SYMBOLS 1 ... Projector, L ... Optical axis, O ... Rotary axis, 32 ... Illumination optical apparatus (illumination optical system), 61a, 61b ... Light-shielding part (1st light-shielding part), 71a, 71b ... Light-shielding part (2nd light-shielding part) 311 ... Light source 320 ... Notch part 320 ... First notch part 325 ... Dimming mechanism (light shielding mechanism) 326 ... Light shielding shutter (light shielding plate part) 326, 327 ... Light shielding shutter (light shielding member) 326a, 327a: tip portion, 328 ... light shielding portion, 329 ... driving portion, 330 ... second notch portion, 352 ... liquid crystal light valve (light modulation device)

Claims (4)

A light source;
An illumination optical system having a light blocking mechanism capable of partially blocking the light flux from the light source;
A light modulation device illuminated by illumination light from the illumination optical system,
The light-shielding portion has a pair of light-shielding plate portions that change the size of the light-shielding region by rotating around a predetermined rotation axis,
When the light shielding plate portion is at the maximum light shielding position, the first light shielding portion extending in a direction substantially orthogonal to the optical axis, and the illumination light exit side with respect to the first light shielding portion, A second light-shielding portion that is inclined with respect to the first light-shielding portion so that a distal end side is separated from the first light-shielding portion, and the first light-shielding portion and the second light-shielding portion are configured by folding one base material. A projector characterized by being configured. The projector according to claim 1, wherein both ends of the folded base material are caulked and fixed to each other. 3. The projector according to claim 1, wherein at least one end portion of the substrate that is folded back is caulked and fixed to a connecting member having a thermal conductivity smaller than that of the substrate. 4. The projector according to claim 1, wherein the base material is folded from a direction intersecting an opening / closing direction of the optical axis and the light shielding plate part. 5.

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